Fatal error : Using $this when not in object context in [duplicate] - php

Question

This question already has answers here:
PHP Fatal error: Using $this when not in object context
(9 answers)
Closed 7 years ago.
I have the below function, But when I run the code make error like:
Fatal error: Using $this when not in object context in E:....
How to fix it. I replace $this-> with self:: but it failed too.
Please help in this regards,
<?php
function cehck_files()
{
$file1 = 'C:\xampp\htdocs\test\test1.php';
$file2 = 'C:\xampp\htdocs\test\test2.php';
$test = $this->compareFiles($file1,$file2,true);
$test_display = $this->toTable($test);
echo "<pre>";
print_r($test_display);
print_r($test);
echo "</pre>";
}
function compareFiles($file1, $file2, $compareCharacters = false) {
return $this->compare(file_get_contents($file1),file_get_contents($file2),$compareCharacters);
}
function compare($string1, $string2, $compareCharacters = false) {
$start = 0;
if ($compareCharacters){
$sequence1 = $string1;
$sequence2 = $string2;
$end1 = strlen($string1) - 1;
$end2 = strlen($string2) - 1;
} else {
$sequence1 = preg_split('/\R/', $string1);
$sequence2 = preg_split('/\R/', $string2);
$end1 = count($sequence1) - 1;
$end2 = count($sequence2) - 1;
}
// skip any common prefix
while ($start <= $end1 && $start <= $end2 && $sequence1[$start] == $sequence2[$start]) {
$start ++;
}
// skip any common suffix
while ($end1 >= $start && $end2 >= $start && $sequence1[$end1] == $sequence2[$end2]) {
$end1 --;
$end2 --;
}
// compute the table of longest common subsequence lengths
$table = self::computeTable($sequence1, $sequence2, $start, $end1, $end2);
// generate the partial diff
$partialDiff =
self::generatePartialDiff($table, $sequence1, $sequence2, $start);
// generate the full diff
$diff = array();
for ($index = 0; $index < $start; $index ++){
$diff[] = array($sequence1[$index], UNMODIFIED);
}
while (count($partialDiff) > 0) $diff[] = array_pop($partialDiff);
for ($index = $end1 + 1; $index < ($compareCharacters ? strlen($sequence1) : count($sequence1)); $index ++) {
$diff[] = array($sequence1[$index], UNMODIFIED);
}
// return the diff
return $diff;
}
function computeTable($sequence1, $sequence2, $start, $end1, $end2) {
$length1 = $end1 - $start + 1;
$length2 = $end2 - $start + 1;
// initialise the table
$table = array(array_fill(0, $length2 + 1, 0));
// loop over the rows
for ($index1 = 1; $index1 <= $length1; $index1 ++) {
// create the new row
$table[$index1] = array(0);
// loop over the columns
for ($index2 = 1; $index2 <= $length2; $index2 ++){
// store the longest common subsequence length
if ($sequence1[$index1 + $start - 1] == $sequence2[$index2 + $start - 1]) {
$table[$index1][$index2] = $table[$index1 - 1][$index2 - 1] + 1;
} else {
$table[$index1][$index2] =
max($table[$index1 - 1][$index2], $table[$index1][$index2 - 1]);
}
}
}
// return the table
return $table;
}
function generatePartialDiff( $table, $sequence1, $sequence2, $start ) {
$diff = array();
// initialise the indices
$index1 = count($table) - 1;
$index2 = count($table[0]) - 1;
// loop until there are no items remaining in either sequence
while ($index1 > 0 || $index2 > 0){
// check what has happened to the items at these indices
if ($index1 > 0 && $index2 > 0 && $sequence1[$index1 + $start - 1] == $sequence2[$index2 + $start - 1]) {
// update the diff and the indices
$diff[] = array($sequence1[$index1 + $start - 1], UNMODIFIED);
$index1 --;
$index2 --;
} elseif ($index2 > 0 && $table[$index1][$index2] == $table[$index1][$index2 - 1]) {
// update the diff and the indices
$diff[] = array($sequence2[$index2 + $start - 1], INSERTED);
$index2 --;
}else{
// update the diff and the indices
$diff[] = array($sequence1[$index1 + $start - 1], DELETED);
$index1 --;
}
}
// return the diff
return $diff;
}
function toTable($diff, $indentation = '', $separator = '<br>') {
$html = $indentation . "<table class=\"diff\">\n";
// loop over the lines in the diff
$index = 0;
while ($index < count($diff)){
// determine the line type
switch ($diff[$index][1]){
// display the content on the left and right
case UNMODIFIED:
$leftCell =
self::getCellContent(
$diff, $indentation, $separator, $index, UNMODIFIED);
$rightCell = $leftCell;
break;
// display the deleted on the left and inserted content on the right
case DELETED:
$leftCell =
self::getCellContent(
$diff, $indentation, $separator, $index, DELETED);
$rightCell =
self::getCellContent(
$diff, $indentation, $separator, $index, INSERTED);
break;
// display the inserted content on the right
case INSERTED:
$leftCell = '';
$rightCell =
self::getCellContent(
$diff, $indentation, $separator, $index, INSERTED);
break;
}
// extend the HTML with the new row
$html .=
$indentation
. " <tr>\n"
. $indentation
. ' <td class="diff'
. ($leftCell == $rightCell
? 'Unmodified'
: ($leftCell == '' ? 'Blank' : 'Deleted'))
. '">'
. $leftCell
. "</td>\n"
. $indentation
. ' <td class="diff'
. ($leftCell == $rightCell
? 'Unmodified'
: ($rightCell == '' ? 'Blank' : 'Inserted'))
. '">'
. $rightCell
. "</td>\n"
. $indentation
. " </tr>\n";
}
// return the HTML
return $html . $indentation . "</table>\n";
}
?>

Answer 1

You are using $this for a function which is not a method of any class.
Instead of
$test = $this->compareFiles($file1,$file2,true);
Use:
$test = compareFiles($file1,$file2,true);
Also, change
return $this->compare(file_get_contents($file1),file_get_contents($file2),$compareCharacters);
To
return compare(file_get_contents($file1),file_get_contents($file2),$compareCharacters);
And to the remaining changes in this way.